Lancing apparatuses are often used for extracting blood of diabetics for measurement of the blood glucose levels. Generally, such a lancing apparatus includes a tubular housing having an open front end and a lancet holder arranged in the housing reciprocally movably. To use the lancing apparatus, a lancet of a disposable type is mounted to the lancet holder. Subsequently, with the front end of the housing held in contact with the skin of a human, the lancet and the lancet holder are advanced toward the front end of the housing so that the needle of the lancet lances the skin of the human. As a result, blood bleeds from the skin, whereby sampling of the blood can be performed.
FIGS. 26A, 26B, 27A and 27B show prior art lancets which are disclosed in JP-U 6-38909, for example.
The lancet 9A shown in FIG. 26A includes a threaded portion 94 and a needle 91. A cap 90A for covering the needle 91 is connected to the lancet 9A. When the threaded portion 94 is inserted into a housing 80 of a lancing apparatus 8 and rotated, the threaded portion is screwed to a threaded hole 82 provided at a front end of a lancet holder 81A of the lancing apparatus, whereby the lancet 9A is mounted to the lancet holder 81A. Thereafter, the cap 90A can be removed from the lancet 9A. After the lancing operation is performed, the cap 90A is reversed as shown in FIG. 26B and inserted into the housing 80. By fitting a hexagonal hole 92 formed in the lancet 90A to a hexagonal part of the lancet 9A and turning the cap, the screwed state of the lancet 9A and the lancet holder 81A is released, whereby the lancet 9A can be removed from the lancet holder 81A.
With such an arrangement, the user need not directly touch the needle 91 of the lancet 9A in mounting the lancet 9A to the lancing apparatus 8 and removing the lancet from the lancing apparatus 8. Therefore, it is possible to eliminate the possibility that the user's hand is hurt by the needle 91 or strained with blood adhering to the needle 91 by lancing.
The lancet 9B shown in FIG. 27A has a circumferential surface formed with projections 93. When the projections 93 are fitted into generally L-shaped grooves 83 formed in a lancet holder 81B of a lancing apparatus, the lancet 9B is held in the lancet holder 81B so as not to drop therefrom. After the lancet 9B is held in the lancet holder 81B in this way, the cap 90B can be removed from the lancet 9B, as shown in FIG. 27B. When the cap 90B is fitted to a portion having a cross-shaped section of the lancet 9B and rotated, the projections 93 can be removed from the grooves 83, whereby the lancet 9B can be removed from the lancet holder 81B. Also with such an arrangement, the user need not directly touch the needle 91, and the same advantages as those of the lancet shown in FIGS. 26A and 26B can be obtained.
However, the above prior art lancets have the following problems.
In the prior art lancet shown in FIGS. 26A and 26B, to remove the lancet 9A from the lancet holder 81A, the lancet 9A need be rotated by using the cap 90A. This rotation operation is troublesome for the user.
Although the cap 90A serves as a tool for rotating the lancet 9A, the cap does not have a function to positively and reliably hold the lancet 9A. Therefore, even when the screwed portion of the lancet 9A and the lancet holder 81A is loosened, the lancet 9A may not be taken out from the threaded hole 82. Further, in taking out the lancet 9A by fitting the lancet 9A to an end of the cap 90A, the lancet 9A may be removed from the cap 90A. Thus, the lancet 9A may not be properly taken out from the housing 80 just by using the cap 90A.
The above problems occur also in the lancet 9B shown in FIGS. 27A and 27B.